A mobile device is able to connect to a wireless access network to perform various different types of communications, such as to establish a call with another endpoint, to access websites, to perform text messaging, and so forth. In some cases, a mobile device is able to transition between different types of wireless access networks according to different access technologies. The transition between different types of wireless access networks can be performed for various reasons, such as due to movement of the mobile device between different geographic points, due to detection of stronger signaling in one of the wireless access networks, or for other reasons.